There exists a need for a material that will fulfill requirements for dynamic seal applications, e.g., O-rings, gaskets, diaphragms, and the like, as well as sealant applications, e.g., fuel tank sealants, coatings, and the like, for current and future high performance aircraft. For example, certain advanced aircraft will have hydraulic systems with seals that must withstand temperatures ranging from -70.degree.F to 400.degree.F.
Currently, only a fluorosilicone system is useful in the -70.degree.F to 400.degree.F range. However, this system is expensive to produce and is only of limited value in seal applications because of its tendency to revert and its poor dynamic performance. This latter deficiency of the system is due to its low tensile stregnth and low elongation. Considerable research has been conducted with the goal of deriving elastomer systems from perfluoroethers and dinitrile N-oxides that might overcome the deficiencies in the fluorosilicone system. However, such work has apparently been unsuccessful because any polymers obtained did not contain the pendent functional groups necessary for curing the polymers.
It is an object of this invention, therefore, to provide poly(perfluoroalkylene oxide)oxadiazles which can be crosslinked so as to provide useful elastomer systems.
Another object of the invention is to provide a process for synthesizing poly(perfluoroalkylene oxide)oxadiazoles containing pendent aromatic nitrile groups.
A further object of the invention is to provide a process for curing poly(perfluoroalkylene oxide)oxadiazoles containing pendent aromatic nitrile groups.
Still another object of the invention is to provide a fluorinated elastomer which is useful at temperatures ranging from about -70.degree.F to 400.degree.F and which possesses outstanding physical properties.
Other objects and advantages of the invention will become apparent to those skilled in the art upon consideration of the accompanying disclosure.